This invention relates to an abnormality diagnosing system and method for high voltage power apparatus, and more particularly to a system and method which will be suitable for diagnosing at least an insulation of a abnormality, a power supply abnormality, and for detection of a mixture of foreign matter.
Conventional abnormality diagnosing techniques for high voltage power machinery or apparatus are of a discrete type. As to an insulation abnormality, reference is made to Japanese Patent Laid-Open No. 2518/1984, Japanese Patent Laid Open No. 41135/1980, Int. Symp. on Gas Insulated Substations, L1(1985) and the like, and as to a power supply abnormality, Japanese Patent Laid-Open No. 31323/1981, IEEE Trans. Power Apparatus and Systems, Vol. PAS-100, No. 6 (1981), pp. 2733-2739, and the like. The Int. Symp. on Gas Insulated Substations, L1, for example, describes means for detecting signals of partial discharge from a few MHz to a few GHz. Japanese Patent Laid-open No. 41135/1980 detects an impingement sound of foreign matter jumping due to the oscillation of GIS or to the electric field and monitors the existence of the foreign matter. Furthermore, as the diagnosis of a power supply abnormality, Japanese Patent Laid-Open No. 117421/1980 proposes a processor having a complicated algorithm for detecting the oscillation from a tank. Document PE-87-7 of Power Technique diagnosing system of substation apparatuses and abnormality diagnosis is made by the employment of an external diagnosis system, primary processing of sensor signals, function bearing between field panels and a center panel, the employment of optical transmission and a computer.
The conventional technique described above contemplates to detect individually the insulation abnormality and power supply abnormality of high voltage power machinery. However, processing techniques of abnormality signals do not always match the needs and sometimes overlook the abnormality signals. Furthermore, a sufficient consideration is not paid to the algorithm of abnormality diagnosis by various signals and the problem remains that highly accurate diagnosis cannot be made from the determination of the factor and degree of abnormality to the determination of position.
For example, although the Symp. on Gas Insulated Substations, L1 describes means for detecting partial discharge as the symptom of an insulation abnormality by detecting a high frequency electrical signal of above several MHz, the document does not discuss means for eliminating noise when the noise is so great that a delicate partial discharge cannot be detected. The same noise problem occurs in means for detecting the jumping oscillation of very small foreign matter by AE (Acoustic Emission), and this problem also exists in detection means of a power supply abnormality.
A document of the Power Technique Research Section of Electric Science Society introduces a diagnosing system of substation apparatuses, but even though such system can detect the abnormality signals, it cannot diagnose qualitatively and quantitatively the abnormality because the correlation between the kind, degree and position of the abnormality and the signal is not known sufficiently. Furthermore, a sufficient consideration is not paid to the consistent system of method of abnormality diagnosis, display, recording and transfer means and the system lacks therefore rationality and economy.